THE first ankle tag that constantly monitors if an offender is still drinking has been fitted to a man for provoking violence outside a nightclub whilst drunk.

The use of "sobriety tags" as part of a year-long pilot scheme was announced by Boris Johnson today.

The Mayor of London said the scheme is targeted at people "getting a bit too tanked up on a Friday night" and becoming involved in violence, such as fights.

Augustine Apraku, 24, from Sutton, south London, was ordered to wear the "sobriety tag" for 80 days after he pleaded guilty to one charge of using abusive language and provoking unlawful violence at Croydon Magistrates' Court.

What we're trying to do is tackle the people who are not habitual problem drinkers, not people involved in domestic violence per se because we need different solutions for that

Boris Johnson, Mayor of London

The Mayor said: "What we're trying to do is tackle the people who are not habitual problem drinkers, not people involved in domestic violence per se because we need different solutions for that.

"But we need to look at people who get just a bit too tanked up on a Friday or Saturday night and get involved in some sort of alcohol related crime, such as affray.

"Rather than lock them up we can help them to beat it by putting this ankle sniffing device on.

"If they drink again they'll be in breach of their sentence and back before the courts.

"I think it's a cheaper, more effective way to help people to beat the booze and to beat violence."

He denied that it would infringe on offenders right to have a drink, adding that their 'civil liberties' would be more affected by going to prison.

The scheme, which measures abstinence by testing the offender's perspiration every 30 minutes for alcohol, is aimed at people who have committed a crime while under the influence of drink but who are not alcohol dependent.

The tags, which can be issued by magistrates' to first-time offenders, must be worn 24 hours a day for up to 120 days.

If any trace is found, an alert will be sent to the offender's probation officer and they can then be recalled to court, where they could face sanctions such as a fine or be re-sentenced.